Mesoscale Growth and Assembly of Bright Luminescent Organolead Halide Perovskite Quantum Wires

The long carrier lifetimes and low nonradiative recombination rates of organic–inorganic hybrid perovskites have opened new avenues in fabrication of highly efficient solar cells, light-emitting diodes, and lasers. Controlling shapes and organization of newly synthesized perovskite nanostructures should greatly expand their practical application. Here, we report a colloidal synthetic approach to the preparation of methylammonium lead bromide (CH 3 NH 3 PbBr 3 ) quantum wires by controlling their surface ligand chemistry to achieve well-defined superstructures. Quantum wire formation was proceeded by the appearance of pearl-necklace assemblies of spherical CH 3 NH 3 PbBr 3 nanocrystals as intermediates formed mainly through dipolar interactions. The diameter of the quantum wires (∼3.8 nm) was found to be larger than the precursor spherical CH 3 NH 3 PbBr 3 nanocrystals (∼2.4 nm). Our experimental findings support mesoscale growth and assembly into CH 3 NH 3 PbBr 3 quantum wires driven by cooperative interactions between nanocrystals caused by van der Waals interactions and chain interdigitation of surface passivating ligands. The quantum wires displayed an aspect ratio as high as 250 with photoluminescence quantum yield of ∼60% and lifetime of ∼90 ns, and were aligned in bundles. Our simple colloidal synthetic approach and detailed characterization will inspire rational design of methodologies to prepare diverse anisotropic semiconductor perovskite nanostructures and superstructures, which together will increase the versatility and performance of perovskite materials in optoelectronic and photovoltaic device applications.